Wikipedia went dark and Google blacked out its logo, as the brainiacs of Silicon Valley tilted at the A-list media giants of Hollywood and New York. At issue were two antipiracy bills that few Americans had even heard of. Suddenly, though, people were buzzing about SOPA and PIPA — short for the Stop Online Piracy Act and the Protect Intellectual Property Act. The clash prompted a remarkable outpouring within the Internet world. One reason for that, says Sandra Aistars, the executive director of the nonprofit Copyright Alliance and a former associate general counsel for Time Warner, is that the Web’s anti-SOPA message is “sexier” than the facts offered up by Hollywood. “Downloading stuff on the Internet for free is cool,” said a person close to Viacom, who spoke on the condition of anonymity so as not to jeopardize his relationship with the company. “Our message isn’t cool.”